Transformer-core structure



TRANSFORMER CORE STRUCTURE Filed June 22, 1927 INVENTOR ATTORNEY Patented Mar. 26, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM F, HENDRY, OF OSSINING, NEW YORK, ASSIGNOR TO MANHATTAN ELEC- TRICAL SUPPLY COMPANY, INC, A CORPORATION OF MASSACHUSETTS.

TRANSFORMER-CORE STRUCTURE.

Application filed June 22,

transformer, consisting of a plurality of differently shaped core elements so formed as to be easily fitted together upon assembly of the core unit.

Another object is to so construct the core elements of a constant current transformer that the core and transformer coils can be quickly and cheaply assembled. 7

Various types of transformers are now known wherein the core is constructed of a plurality of thin sheets of magnetic material placed one on top of the other in overlapping relation. consist of two separate windings mounted on a closed laminated core. These cores are roughly of the form of a square or rectangle and are built up of a plurality of straight pieces of thin iron or similar material, several pieces of which form each leg of core and all of the legs of which are so constructed as to dovetail together with the other legs.

In the construction of constant current transformers and other transformers wherein the core consists of an A-shaped section, it is of course possible to make a core consisting of a plurality of straight pieces mutually interlocked in the manner above mentioned, but this process involves considerable expense and requires careful assembling of the transformer.

According to my invention a constant current transformer may be conveniently constructed having a single coil primary and a double coil secondary winding, all of the said windings being mounted on a closed magnetic core having a magnetic shunt consisting of a pair of legs extending out from the core in such a manner as to tend to shunt the magnetic circuit of the primary core. For ease of construction of such a transformer, I have provided a core which is built up of a plurality of pairs of differently shaped elements which fit together in such a manner as to form a substantially A-shaped core. In the finished transformer the rimary winding is mounted on the cross Ear of the A, two secondary windings are Many of these transformers 1927. Serial No. 200,674.

mounted on the two legs extended upwardly from the cross bar of the A and the magnetic shunt is comprised of the two lower legs of the A. Each pair of core elements consists of a J-shaped section and an L-shaped or a right angled shaped section. These two sections are fitted together with their edges in contact in such a manner that one leg of the L extends from the short upturned portion of the J acrossto an intermediate point of the long upturned portion of the J and the other leg of the L-shaped portion extends upwardly away from the short upturned' portion of the J. Such aconstruction as this allows a core to be quickly and easily constructed, as it is necessary merely to hold the three coil sections in a jig and insert the core sections alternately to build up a core.

Referring to the drawings, Fig. 1 illustrates the first step in assembling a core for a transformer, in accordance with my invention; Fig. 2 illustrates the core after the completion of the step shown in Fig. 1; Fig. 3 illustrates the second step in assembling the core; Fig. 4 illustrates the core i fter the completion of the step shown in ig. 3.

Reference numeral 1 indicates the primary winding of the transformer; 2, one coil of the secondary winding; 3, the other coil of the secondary winding; 4, a J-shaped section of the core; and 5, an L or right angled section of the core.

In assembling the transformer the three coil windings are held in the position shown in Fig. 1 by suitable means, with the two secondary coils placed parallel to each other a suitable distance apart and the rimary coil placed at right angles to and etween the axes of the secondarycoils and spaced slightly from the ends of the said coils. With the coils so placed, one of the J-shaped sections of the core 'is thrust through the two secondary coils in the direction illustrated by the arrow in Fig. 1. Then an L shaped section is thrust in through the primary coil in the direction also illustrated by an arrow. WVhen the two core sections have been thrust through the windings, the partially formed core has the form shown in Fig. 2. The next step as shown in Fig. 3 is to thrust through the two secondary coils another J-shaped section, 6, which is in the reversed position from the first J-sha section, then another L-shaped section, is thrust through the f1p'rimar coil in the opposite direction to the rst L-s iaped direction, which leaves the core in the form shown in Fig. 4. This process is continued by the insertion of J and L shaped sections alternately in the manner just described until the core attains the desired thickness.

The secondary winding is made two portions in order to keep the overall dimensions and weight of the transformer as small as possible, thus making a smaller transformer than would be possible if the secondary coil were made in one section. It will be obvious that with different transformers the length of the open legs should be adjusted to give the desired results, in the manner well known to the art.

While Ihave described my invention as applied to a constant current transformer, it is to be understood that the invention is equally applicable to the other types of,

transformers wherein a core of this shape is desirable.

It will be obvious to those skilled in the art that the present disclosure is intended merely to illustrate one form which my invention may take and that the invention is capable of a wide variety of modifications and adaptations without a departure from the spirit of the invention as set forth in the appended claims. 7

What I claim is: I

1. A constant current transformer having a single coil primary and a double coil secondary, the core of said=transformer comprising 'a J-shaped section and an L-shaped section, the secondary coils being positioned on the two upturned legs ofthe J-shaped section adjacent the closed end thereof, the primar coil being positioned on one leg of the L-s aped section and the two core sections being put together in A-shape, with the leg of the L-shaped section which bears the primary coilextending between the two upturned portions of the J-shapcd section.

2. A constant current'transformer having a core made up of J-shaped sections and L-shaped sections, a primary coil positioned on one leg of the L-shaped section, a secondary coil positioned on one of the upturned legs of the J-shaped section, the two core sections being assembled in H-shape with the leg-of the L-shaped section bearing the primary coil extending between the upturned portions of the J-shaped section.

In testimony whereof, I have signed my name to this specification this 17th day of June, 1927.

. WILLIAM F. HENDRY. 

